Some of nature's courtship rituals are elaborate, others rather discrete. For instance the male woodcock -- an odd-looking, fist-sized bird with an outlandish 2-inch-long bill -- performs his ceremony under the cover of darkness. It's called the "Sky Dance."

The woodcock is normally a reclusive bird, it's cryptic coloration blending perfectly with the leafy forest floor. During courtship, however, the male woodcock attempts to become obvious to a female.

It's April and the stage is set. The curtain goes up at dusk, and although the Sky Dance is rated X, general audiences are admitted.

Sky Dance could be playing in your back yard, yet you may be unaware. The show starts at 20 minutes after sunset when, to a woodcock, the light is a romantic "just so.'' Don't worry about finding a seat. Sky Dance has been playing for eons, yet the theaters remain nearly audience-free.

Woodcock prefer a clear, calm, warm evening for lovemaking, and those are also the best conditions for viewing. According to some, at exactly 22 minutes after sunset, or when the light level reaches .05 foot-candles, the male woodcock flies to his stage. Personally, I have found the timing to be less precise, but courtship activity does begin nearly on that schedule. The stage can be any opening or field edge in typical woodcock habitat. Because woodcock feed primarily on earthworms, they prefer lowlands that are damp but not wet, in a mix of young alder, willow and aspen. A barren log landing in an eight- to 10-year-old aspen clear-cut is an ideal woodcock courtship site.

Bill Marchel, Special to the Star Tribune

About 20 minutes after sunset a male woodcock flys to an opening in a new growth forest. There he will perform his springtime courstship ritual, often called the Sky Dance.

A few years ago I amazed a friend when I took him to see the Sky Dance in a tiny clearing among aspen trees just a stone's throw from my home near Brainerd. On previous evenings I had photographed a male woodcock that used the opening as his stage.

We had arrived a bit early, and I took the time to explain to my friend the woodcock's courtship ritual and what he could expect to witness. At about 20 minutes after sunset I told my friend we needed to be quiet, that a woodcock will fly in any minute. Shortly, the plump little bird appeared, flying like a giant bat silhouetted against the darkening sky. It landed within 10 feet of us.

"Do you have that bird trained?" my friend later asked.

On spring evenings, when the light is right, the male woodcock will fly out of obscurity and alight at his predetermined stage. Upon arriving, the woodcock begins to call, emitting a throaty peent every three or four seconds. Each peent is preceded by a hiccup-like sound, although oddly, the strange call is inaudible to some humans. After a few peents in one direction, the bird pivots roughly 90 degrees and calls in a new direction, and so on until after a minute or so he has declared in all directions his affections to females, and warnings to other males.

Then without signal, he takes flight. As he leaves his stage, the woodcock can be seen silhouetted against the western sky as it flies low, parallel to the ground for a distance before rising in wide arcs. His circles become steeper and smaller until he is hundreds of feet high. During his flight, the bird emits a musical twitter as air rushes through odd-shaped primary wing feathers. Upon reaching its peak, the sky dancer hovers momentarily before pitching toward Earth on folded wings. Slipping sideways as it tumbles down, the bird alternately dives and then checks its fall, all the while uttering a melodic tune as it plummets earthward, returning to roughly the spot where the performance began.

The entire ritual is repeated again and again for about 45 minutes, at which point the act can be followed only by ear, the overhead sky being too dark to see even a silhouette.

Before daybreak, when again the light is just right, the performance is repeated.

During the ritual, if a male successfully attracts a female, they will mate. Subsequently, she will nest and raise the young on her own; a typical woodcock nest holds four eggs.

Somehow it seems fitting a bird as secretive as a woodcock would use the cover of darkness for its spectacular display.

Male woodcock begin courting in late March or early April and continue through mid-May, sometimes even into June.

Among birders, few avian courtship rituals rate as highly.

Bill Marchel is a wildlife photographer and outdoors columnist. He lives near Brainerd, Minn.